CN110573714A

CN110573714A - compressed air storage power generation device and compressed air storage power generation method

Info

Publication number: CN110573714A
Application number: CN201880027687.4A
Authority: CN
Inventors: 户岛正刚; 松田治幸; 久保洋平
Original assignee: Kobe Steel Workshop
Current assignee: Kobe Steel Workshop; Kobe Steel Ltd
Priority date: 2017-04-26
Filing date: 2018-04-06
Publication date: 2019-12-13
Also published as: JP2018184907A; US20200131989A1; US10995665B2; EP3628841A4; EP3628841A1; JP6731377B2; WO2018198724A1

Abstract

a compressed air storage power generation device (1) is provided with: an inert gas source (25) for providing an inert gas; an inert gas flow path system (6); and a flow path switching unit (28). The inert gas flow path system (6) fluidly connects the gas phase section (17b) of the high-temperature heat storage section (17), the gas phase section (18b) of the low-temperature heat storage section (18), and the inert gas source (25) to each other. The flow path switching unit (28) can switch the inert gas flow path system (6) at least between a state in which the inert gas source (25) is in communication with both the high-temperature heat storage unit (17) and the low-temperature heat storage unit (18), and a state in which the inert gas source (25) is blocked from both the high-temperature heat storage unit (17) and the low-temperature heat storage unit (18).

Description

Compressed air storage power generation device and compressed air storage power generation method

Technical Field

the invention relates to a compressed air storage power generation device and a compressed air storage power generation method.

Background

Compressed air storage (CAES) is known as one of techniques for smoothing or averaging fluctuating, unstable power generation output. In the compressed air storage power generation apparatus using this technology, when excess generated power is generated, compressed air is passed through the compressor to store energy as air pressure, and when necessary, the expander is operated with the compressed air and reconverted to electricity in the generator.

patent document 1 discloses a compressed air storage power generation device including a heat medium flow path including a 1 st heat exchanger, a high-temperature heat medium tank, a 2 nd heat exchanger, and a low-temperature heat medium tank. The compressed air discharged from the compressor is heat-recovered by heat exchange with the heat medium in the 1 st heat exchanger, and then stored in the accumulator tank. The heat medium heated by the heat recovery is recovered to the high-temperature heat medium tank. The compressed air stored in the accumulator tank is heated by heat exchange with the heat medium in the 2 nd heat exchanger, and then supplied to the expander. The heat medium cooled by the heat exchange is recovered to the low-temperature heat medium tank. The heat medium flow path is provided with a pump for circulating the heat medium.

Documents of the prior art

Patent document

Patent document 1: JP 2016-211436

Disclosure of Invention

Summary of the invention

Problems to be solved by the invention

The prior art documents relating to the compressed air storage/power generation device including patent document 1 do not suggest any particular suppression of the deterioration of the heat medium.

The invention aims to restrain the deterioration of a heat medium in a compressed air storage power generation device.

Means for solving the problems

The invention according to claim 1 provides a compressed air storage power generation device including: a motor driven by a variable input power; a compressor mechanically connected to the motor for compressing air; a pressure accumulation unit that is fluidly connected to the compressor and that accumulates compressed air generated by the compressor; an expander fluidly connected to the accumulator and driven by the compressed air supplied from the accumulator; a generator mechanically connected to the expander; a 1 st heat exchanger for exchanging heat between the compressed air generated by the compressor and a heat medium to raise the temperature of the heat medium; a high-temperature heat storage unit which is fluidly connected to the 1 st heat exchange unit and stores the heat medium after the heat exchange in the 1 st heat exchange unit; a 2 nd heat exchange unit fluidly connected to the high-temperature heat storage unit, for performing heat exchange between the heat medium supplied from the high-temperature heat storage unit and the compressed air supplied from the heat storage unit to the expander to raise a temperature of the compressed air; a low-temperature heat storage unit which is fluidly connected to the 2 nd heat exchange unit and stores the heat medium subjected to heat exchange in the 2 nd heat exchange unit; an inert gas source that provides an inert gas; an inert gas flow path system that fluidly connects the gas phase portion of the high-temperature heat storage portion, the gas phase portion of the low-temperature heat storage portion, and the inert gas source to each other; and a flow path switching unit capable of switching at least a state in which the inert gas flow path system is in communication with both the high-temperature heat storage unit and the low-temperature heat storage unit and a state in which the inert gas source is blocked from both the high-temperature heat storage unit and the low-temperature heat storage unit.

Since the inert gas is supplied to the high-temperature heat storage portion and the low-temperature heat storage portion from the inert gas source via the inert gas passage system, oxidative deterioration of the heat medium stored in these tanks can be suppressed or prevented. The gas phase portion of the high-temperature heat storage portion and the gas phase portion of the low-temperature heat storage portion are fluidly connected to each other via an inert gas flow path system. That is, the inert gas can move between the high-temperature heat storage portion and the low-temperature heat storage portion via the inert gas flow path system. Therefore, the amount of inert gas newly supplied from the inert gas source to the high-temperature heat storage portion and the low-temperature heat storage portion, that is, the inert gas consumption amount can be reduced.

specifically, the compressed air storage power generation device further includes: a control unit that controls the flow path switching unit, wherein the state of the inert gas flow path system that can be switched by the flow path switching unit includes: a 1 st state in which the high-temperature heat storage portion and the low-temperature heat storage portion are in communication with each other, and the inert gas source is blocked from both the high-temperature heat storage portion and the low-temperature heat storage portion; a 2 nd state in which the high-temperature heat storage portion and the low-temperature heat storage portion are blocked from each other, and the inert gas source is blocked from both the high-temperature heat storage portion and the low-temperature heat storage portion; a 3 rd state in which the inert gas source is communicated with the low-temperature heat storage portion, and the high-temperature heat storage portion is blocked from the low-temperature heat storage portion and the inert gas source; and a 4 th state in which the inert gas source communicates with the high-temperature heat storage unit, while the low-temperature heat storage unit is blocked from the high-temperature heat storage unit and the inert gas source, the control unit switching the inert gas flow path system to any of the 1 st to 4 th states by the flow path switching unit based on at least which of a charging operation and a power generation operation is performed, and whether or not a 1 st pressure that is a pressure of the gas phase of the high-temperature heat storage unit is equal to or higher than a 2 nd pressure that is a pressure of the gas phase of the low-temperature heat storage unit.

More specifically, the compressed air storage power generation device can be set to a 1 st mode in which reduction of inert gas consumption is prioritized over reduction of power consumption and a 2 nd mode in which reduction of power consumption is prioritized over reduction of inert gas consumption, in the charging operation in the 1 st mode, if the 1 st pressure is equal to or higher than the 2 nd pressure, the control section switches the inert gas flow path to the 1 state by the flow path switching section, in the charging operation in the 1 st mode, if the 1 st pressure is not equal to or higher than the 2 nd pressure, the control section switches the inert gas flow path to the 2-state by the flow path switching section, in the charging operation in the 2 nd mode, the control unit switches the inert gas flow path to the 3 rd state by the flow path switching unit.

The control unit switches the inert gas flow path system by the flow path switching unit in this manner, thereby reducing the amount of inert gas consumed in the charging operation in the 1 st mode and reducing the amount of power consumed by the compressed air storage power generation device in the charging operation in the 2 nd mode.

In the power generation operation in the 1 st mode, the control unit may switch the inert gas flow path to the 2 nd state by the flow path switching unit if the 1 st pressure is equal to or higher than the 2 nd pressure, may switch the inert gas flow path to the 1 st state by the flow path switching unit if the 1 st pressure is not equal to or higher than the 2 nd pressure in the power generation operation in the 1 st mode, and may switch the inert gas flow path to the 4 th state by the flow path switching unit in the power generation operation in the 2 nd mode.

The control unit switches the inert gas flow path by the flow path switching unit in this manner, thereby reducing the amount of inert gas consumed in the power generation operation in the 1 st mode and reducing the amount of power consumed by the compressed air storage power generation device in the power generation operation in the 2 nd mode.

Alternatively, in the charging operation, the control unit may switch the inert gas flow path to the 1 state by the flow path switching unit if the 1 st pressure is equal to or higher than the 2 nd pressure, and may switch the inert gas flow path to the 2 state by the flow path switching unit if the 1 st pressure is not equal to or higher than the 2 nd pressure.

Further, the control unit may switch the inert gas flow path to the 2 nd state by the flow path switching unit when the 1 st pressure is equal to or higher than the 2 nd pressure during a power generating operation, and may switch the inert gas flow path to the 1 st state by the flow path switching unit when the 1 st pressure is not equal to or higher than the 2 nd pressure during the power generating operation.

The 2 nd aspect of the present invention provides a compressed air storage power generation method for preparing a compressed air storage power generation device, the compressed air storage power generation device including: a motor driven by a variable input power; a compressor mechanically connected to the motor for compressing air; a heat storage unit that is fluidly connected to the compressor and stores compressed air generated by the compressor; an expander fluidly connected to the heat storage unit and driven by the compressed air supplied from the heat storage unit; a generator mechanically connected to the expander; a 1 st heat exchanger for exchanging heat between the compressed air generated by the compressor and a heat medium to raise the temperature of the heat medium; a high-temperature heat storage unit which is fluidly connected to the 1 st heat exchange unit and stores the heat medium subjected to heat exchange in the 1 st heat exchange unit; a 2 nd heat exchanger fluidly connected to the high-temperature heat storage tank, for performing heat exchange between a heat medium supplied from the high-temperature heat storage unit and the compressed air supplied from the heat storage unit to the expander to raise a temperature of the compressed air; a low-temperature heat storage unit which is fluidly connected to the 2 nd heat exchange unit and stores the heat medium subjected to heat exchange in the 2 nd heat exchange unit; an inert gas source that provides an inert gas; an inert gas flow path system that fluidly connects the gas phase portion of the high-temperature heat storage portion, the gas phase portion of the low-temperature heat storage portion, and the inert gas source to each other; and a flow path switching unit capable of switching between a communication state and a blocking state of the inert gas flow path system, wherein the state of the inert gas flow path system switchable by the flow path switching unit includes: a 1 st state in which the high-temperature heat storage portion and the low-temperature heat storage portion are in communication with each other, and the inert gas source is blocked from both the high-temperature heat storage portion and the low-temperature heat storage portion; a 2 nd state in which the high-temperature heat storage portion and the low-temperature heat storage portion are blocked from each other, and the inert gas source is blocked from both the high-temperature heat storage portion and the low-temperature heat storage portion; a 3 rd state in which the inert gas source is communicated with the low-temperature heat storage portion, and the high-temperature heat storage portion is blocked from the low-temperature heat storage portion and the inert gas source; and a 4 th state in which the inert gas source is communicated with the high-temperature heat storage unit, and the low-temperature heat storage unit is blocked from the high-temperature heat storage unit and the inert gas source, and the inert gas flow path system is switched to any of the 1 st to 4 th states based on at least which of a charging operation and a power generation operation the compressed air storage power generation device is in, and whether or not a 1 st pressure that is a pressure of the gas phase of the high-temperature heat storage unit is equal to or higher than a 2 nd pressure that is a pressure of the gas phase of the low-temperature heat storage unit.

ADVANTAGEOUS EFFECTS OF INVENTION

according to the present invention, deterioration of the heat medium in the compressed air storage power generation device can be suppressed.

Drawings

Fig. 1 is a schematic configuration diagram of a compressed air storage power generation system according to embodiment 1 of the present invention.

Fig. 2 is a schematic configuration diagram of a compressed air storage power generation system according to embodiment 2 of the present invention.

fig. 3 is a flowchart for explaining switching of valves during the charging operation in embodiment 2.

FIG. 4 is a schematic configuration diagram showing the setting of the opening and closing of a valve during a charging operation (N)₂Consumption reduction priority, P1 ≧ P2).

FIG. 5 is a schematic configuration diagram showing the setting of the opening and closing of a valve during a charging operation (N)₂Consumption reduction priority, P1 < P2).

Fig. 6 is a schematic configuration diagram showing the setting of the opening and closing of the valve during the charging operation (power consumption reduction priority, P1 ≧ P2).

Fig. 7 is a schematic configuration diagram showing the setting of the opening and closing of the valve during the charging operation (power consumption reduction priority, P1 < P2).

Fig. 8 is a flowchart for explaining switching of the valves during the power generating operation in embodiment 2.

FIG. 9 is a schematic configuration diagram showing the setting of the opening and closing of the valve during the power generating operation (N)₂Consumption reduction priority, P1 ≧ P2).

FIG. 10 is a schematic configuration diagram showing the setting of the opening and closing of the valve during the power generating operation (N)₂Consumption reduction priority, P1 < P2).

FIG. 11 is a schematic configuration diagram showing the setting of the opening and closing of a valve during power generation operation (power consumption reduction priority, P1 ≧ P2).

Fig. 12 is a schematic configuration diagram showing the setting of the opening and closing of the valve during the power generating operation (power consumption reduction priority, P1 < P2).

Fig. 13 is a flowchart for explaining switching of valves during the charging operation in embodiment 3.

Fig. 14 is a flowchart for explaining switching of the valves during the power generating operation in embodiment 3.

Fig. 15 is a flowchart for explaining switching of valves during the charging operation in embodiment 4.

Fig. 16 is a flowchart for explaining switching of the valves during the power generating operation in embodiment 4.

Detailed Description

(embodiment 1)

A compressed air storage (CAES) power generation apparatus 1 averages output variations of a power generation apparatus 2 that generates power using renewable energy, supplies power to an electric power grid 3, and supplies power to the electric power grid 3 in accordance with variations in power demand.

Referring to fig. 1, a CAES power generation apparatus 1 of the present embodiment includes an air flow path system 4, a heat medium flow path system 5, and an inert gas flow path system 6.

(air flow path System)

The air flow path system 4 is provided with a compressor 8, a 1 st heat exchanger (1 st heat exchange unit) 9, a pressure accumulation tank (pressure accumulation portion) 10, a 2 nd heat exchanger (2 nd heat exchange unit) 11, and an expander 12. The air flow path system 4 includes air flow paths 13a to 13 d.

The compressor 8 is mechanically connected to a motor 14. The power receiving and generating device 2 is electrically connected to the motor 14. The power generation device 2 generates power by renewable energy such as wind power, sunlight, solar heat, and waves. The motor 14 is driven by the fluctuating input power from the power generation device 2. The motor 14 may be powered from the electrical system. The suction port 8a of the compressor 8 is fluidly connected to an air flow path 13a for suction. The discharge port 8b of the compressor 8 is fluidly connected to the accumulator tank 10 via an air flow passage 13 b. The 1 st heat exchanger 9 is provided in the air flow path 13 b.

The compressor 8 of the present embodiment is a screw type. Since the screw compressor 8 can control the rotational speed, it can respond well to the irregularly varying input power, and is preferable as a component of the CAES power generation apparatus 1. The compressor 8 may be a compressor other than a scroll type, turbine type, or reciprocating type screw type compressor.

The accumulator tank 10 can store compressed air and accumulate it as energy. The accumulator tank 10 is fluidly connected to the air supply port 12a of the expander 12 through an air flow passage 13 c. The 2 nd heat exchanger 11 is provided in the air flow path 13 c.

The expander 12 is mechanically connected to a generator 15. The generator 15 is electrically connected to the power system 3. The exhaust port 12b of the expander 12 is fluidly connected to an air flow path 13d for exhaust.

The expander 12 of the present embodiment is a screw type. The screw-type expander 12 is preferably used as a component of the CAES power generation apparatus 1 in that rotation speed control is possible. The expander 12 may be an expander other than a scroll type, a turbine type, or a reciprocating type screw type expander.

(Heat medium flow path System)

the heat medium flow path system 5 is provided with a 1 st heat exchanger 9, a high-temperature heat medium tank (high-temperature heat storage portion) 17, a 2 nd heat exchanger 11, and a low-temperature heat medium tank (low-temperature heat storage portion) 18 in this order. The heat medium flow path system 5 includes heat medium flow paths 19a and 19 b. The liquid heat medium is circulated through the heat medium flow path system 5 by pumps 21A and 21B described later. The type of the heat medium is not particularly limited, and for example, a mineral oil-based, glycol-based, or synthetic oil-based heat medium can be used.

The high-temperature heat medium tank 17 has a portion (liquid phase portion 17a) for storing the heat medium and a portion filled with N without storing the heat medium₂A gas phase portion 17b of gas (inert gas). Similarly, a liquid phase part 18a for storing the heating medium and N is filled in the low temperature heating medium tank 18₂A gas phase portion 18b of the gas.

The heat medium flow path 19a is fluidly connected to the liquid phase portion 17a of the high temperature heat medium tank 17 and the liquid phase portion 18a of the low temperature heat medium tank 18. In the heat medium flow path 19a, as described later in detail, the heat medium flows from the low-temperature heat medium tank 18 to the high-temperature heat medium tank 17. The 1 st heat exchanger 9 is provided in the heat medium flow path 19 a. The heat medium flow path 19a includes a valve V4 that can be opened and closed by a controller 37 described later, and a pump 21A between the low-temperature heat medium tank 18 and the 1 st heat exchanger 9. The heat medium flow path 19a includes a check valve 22A between the 1 st heat exchanger 9 and the high-temperature heat medium tank 17. The check valve 22A allows the flow of the heating medium to the high temperature heating medium tank 17, and blocks the flow of the heating medium in the opposite direction thereto.

The heat medium flow path 19b is fluidly connected to the liquid phase portion 17a of the high temperature heat medium tank 17 and the liquid phase portion 18a of the low temperature heat medium tank 18. In the heat medium flow path 19b, as described later in detail, the heat medium flows from the high temperature heat medium tank 17 to the low temperature heat medium tank 18. The heat medium flow path 19b is provided with the 2 nd heat exchanger 11. The heat medium flow path 19B includes an openable/closable valve V5 and a pump 21B between the high-temperature heat medium tank 17 and the 2 nd heat exchanger 11. The heat medium flow path 19B includes a check valve 22B between the 2 nd heat exchanger 11 and the low-temperature heat medium tank 18. The check valve 22B allows the flow of the heating medium to the low temperature heating medium tank 18 but blocks the flow of the heating medium in the opposite direction thereto.

(inert gas flow path System)

the inert gas flow path system 6 connects the gas phase part 17b of the high temperature heat medium tank 17, the gas phase parts 18b and N of the low temperature heat medium tank 18₂Gas cylinders (inert gas sources) 25 are fluidly connected to each other. May also be substituted for N₂A gas cylinder 25, and N such as Ar₂Inert gas sources other than inert gas.

The inert gas passage system 6 in the present embodiment includes an inert gas passage 26a that fluidly connects the gas phase portion 17b of the high temperature heat medium tank 17 and the gas phase portion 18b of the low temperature heat medium tank 18. The inert gas passage system 6 further includes inert gas passages 26a and N₂The gas cylinder 25 is fluidly connected to an inert gas flow path 26 b. The inert gas flow path 26b is provided with a gas flow path for introducing N₂The pressure reducing valve 27 of the gas cylinder 25 that reduces the supply pressure to a given pressure.

a flow path switching unit 28 for switching the communication state of the inert gas flow path system 6 is provided. In the present embodiment, the flow path switching unit 28 is constituted by a single valve V1 that can be controlled to open and close. The valve V1 is provided in the inert gas passage 26b on the inert gas passage 26a side of the pressure reducing valve 27.

The high-temperature heat medium tank 17 is provided with N for detecting the pressure of the gas phase portion 17b, i.e., for filling₂a pressure sensor 31A of the pressure P1 of the gas. The high-temperature heat medium tank 17 is provided with a relief valve 32A that opens when the pressure P1 exceeds a threshold value, and that releases N in the gas phase portion 17b₂The gas is discharged to the outside. Similarly, the low-temperature heat medium tank 18 is provided with N for detecting the pressure of the gas phase portion 18b, that is, the pressure of the gas phase portion₂A pressure sensor 31B for the pressure P2 of the gas, and a safety valve 32B.

Since the high temperature heat medium tank 17 and the low temperature heat medium tank 18 are fed with N₂The gas cylinder 25 is supplied with N via inert gas flow paths 26a, 26b₂Therefore, oxidative deterioration of the heat medium stored in these tanks can be suppressed or prevented.

(compressor component)

The compressor 8, the motor 14, the 1 st heat exchanger 9, and the pump 21A constitute a compressor unit 34. The compressor unit 34 may be a multistage type including a plurality of compressors, and may include a plurality of 1 st heat exchangers.

(Generator component)

The expander 12, the generator 15, the 2 nd heat exchanger 11, and the pump 21B constitute a generator unit 35. The generator unit 35 may be a multistage type including a plurality of expanders, and may include a plurality of 2 nd heat exchangers.

(control device)

In the CAES power generation apparatus 1, the controller 37 collectively controls various components based on various inputs (for example, the pressures P1 and P2 detected by the pressure sensors 31A and 31B). Such elements include the motor 14 for driving the compressor 8, the pumps 21A and 21B, and the valves V1, V4, and V5. The control device 37 includes hardware including storage devices such as a CPU (Central Processing Unit), a RAM (Random Access Memory), and a ROM (Read Only Memory), and software installed therein.

(Charge running)

During the charging operation, the pump 21A is operated, and the pump 21B is not operated. Further, the valve V4 is opened, and the valve V5 is closed.

during the charging operation, the motor 14 is driven by the fluctuating electric power input from the power generation device 2, and the compressor 8 is driven by the motor 14. The compressor 8 sucks and compresses air supplied through the air flow path 13a from the suction port 8a to generate compressed air. The compressed air discharged from the discharge port 8b of the compressor 8 is pressurized and sent to the pressure storage tank 10 through the air flow path 13b, and is stored in the pressure storage tank 10. That is, the pressure accumulation tank 10 stores compressed air and accumulates it as energy. The compressed air passes through the 1 st heat exchanger 9 before being delivered under pressure to the accumulator tank 10.

During the charging operation, the heat medium stored in the low-temperature heat medium tank 18 by the pump 21A is sent to the high-temperature heat medium tank 17 through the heat medium flow path 19 a. The heating medium passes through the 1 st heat exchanger 9 before being sent to the high temperature heating medium tank 17.

The compressed air discharged from the discharge port 8b of the compressor 8 is heated to a high temperature by the compression heat generated during compression. In the 1 st heat exchanger 9, the compressed air is cooled and the heat medium is heated by heat exchange between the heat medium and the compressed air. Therefore, the compressed air cooled by the heat exchange in the 1 st heat exchanger 9 is stored in the pressure accumulation tank 10. In the high-temperature heat medium tank 17, the heat medium heated after the heat exchange in the 1 st heat exchanger 9 is stored.

(operation by Power Generation)

During the power generating operation, the pump 21B is operated, and the pump 21A is not operated. Further, the valve V5 is opened, and the valve V4 is closed.

During the power generating operation, the compressed air sent from the accumulator tank 10 is supplied to the air supply port 12a of the expander 12 through the air flow path 13 c. The compressed air passes through the 2 nd heat exchanger 11 before being provided to the expander 12. The expander 12 is operated by the compressed air supplied to the air supply port 12a, and the generator 15 is driven. The power generated at the generator 15 is supplied to the power system 3. The air expanded in the expander 12 is exhausted from the exhaust port 12b through the air flow path 13 d.

During the power generating operation, the heat medium stored in the high-temperature heat medium tank 17 by the pump 21B is sent to the low-temperature heat medium tank 18 through the heat medium flow path 19B. The heating medium passes through the 2 nd heat exchanger 11 before being sent to the high temperature heating medium tank 17.

In the expander 12, the temperature of the air decreases due to heat absorption during expansion. For this reason, it is preferable that the compressed air supplied to the expander 12 is at a high temperature. In the 2 nd heat exchanger 11, the compressed air is heated by heat exchange between the heat medium and the compressed air, and the heat medium is cooled. Therefore, the expander 12 is supplied with the compressed air whose temperature has been raised by the heat exchange in the 2 nd heat exchanger 11. In addition, the low-temperature heat medium tank 18 stores the temperature-reduced heat medium after the heat exchange in the 2 nd heat exchanger 11.

(N₂Control of gas filling)

The opening/closing control of the valve V1 constituting the flow path switching unit 28 will be described below. In the controller 37, the valve V1 is controlled based on the pressures P1, P2 of the gas phase parts 17B, 18B of the high temperature heat medium tank 17 and the low temperature heat medium tank 18 detected by the pressure sensors 31A, 31B. The valve V1 may be controlled based on only the pressure detected by either of the pressure sensors 31A, 31B. In embodiments 2 to 3 described later, the control of the flow path switching unit 28 is different between the charging operation and the power generating operation, but in the present embodiment, the opening and closing control of the valve V1 is not different between the charging operation and the power generating operation.

The controller 37 opens and closes the valve V1 based on the comparison result between the pressures P1, P2 of the gas phase portions 17b, 18b and a predetermined threshold value. The threshold value is related to the N to be filled in the high temperature heat medium tank 17 and the low temperature heat medium tank 18₂The minimum value of gas corresponds.

when the pressures P1, P2 of the gas phase portions 17b, 18b are equal to or higher than the threshold value, the valve V1 is maintained closed. Even if the valve V1 is closed, the gas phase part 17b of the high temperature heat medium tank 17 and the gas phase part 18b of the low temperature heat medium tank 18 are in fluid communication with each other via the inert gas flow path 26 a.

When the pressures P1, P2 of the gas phase portions 17b, 18b are lower than the threshold values, the valve V1 is opened. When the valve V1 is opened, the valve is switched from N₂The gas cylinder 25 supplies N to the high temperature heat medium tank 17 and the low temperature heat medium tank 18 via the inert gas flow paths 26a, 26b₂A gas.

in the charging operation, the heat medium is flowed to the high-temperature heat medium tank 17 through the heat medium flow path 19a by the pump 21A. On the other hand, during the power generation operation, the heat medium is passed through the heat medium passage 19B by the pump 21B and flows into the low-temperature heat medium tank 18. Generally, the charging operation time is longer than the power generation operation time due to the relationship of the charging and discharging efficiency. Due to this difference in operating time, the amount of the heat medium stored in the high-temperature heat medium tank 17 tends to increase compared to the amount of the heat medium stored in the low-temperature heat storage tank 18.

The heat medium stored in the high-temperature heat medium tank 17 is heated by heat recovery from the compressed air in the 1 st heat exchanger 9. For this reason, the heat medium in the high-temperature heat medium tank 17 tends to thermally expand.

Due to the above 2 tendencies, the rise of the liquid level of the heating medium in the high temperature heating medium tank 17 is more significant than the rise of the liquid level of the heating medium in the low temperature heating medium tank 18. In other words, the volume of the gas phase portion 17b of the high temperature heat medium tank 17 tends to be relatively decreased, and the volume of the gas phase portion 18b of the low temperature heat medium tank 18 tends to be relatively increased. However, even when the valve V1 is closed, the gas phase portion 17b of the high temperature heat medium tank 17 and the gas phase portion 18b of the low temperature heat medium tank 18 are fluidly connected to each other via the inert gas flow path 26 a. That is, the inert gas can move between the high-temperature heat medium tank 17 and the low-temperature heat medium tank 18 through the inert gas flow path 26a, and the pressure of the gas phase portion 17b of the high-temperature heat medium tank 17 and the pressure of the gas phase portion 18b of the low-temperature heat medium tank 18 are equalized. Therefore, the number of slave N can be reduced₂The gas cylinder 25 newly supplies the amount of inert gas, i.e., the inert gas consumption amount, to the high temperature heat medium tank 17 and the low temperature heat medium tank 18. In addition to the inert gas flow path system 6, the heat medium flow path system 5 including the high-temperature heat medium tank 17 and the low-temperature heat medium tank 18 can also make the pressure level uniform as a whole.

(embodiment 2)

referring to fig. 2, a CAES power generation apparatus 1 according to embodiment 2 of the present invention differs from embodiment 1 in the following point. The other device configuration of the present embodiment is the same as that of embodiment 1, and the same reference numerals are given to the same or similar elements as those of embodiment 1.

the flow path switching unit 28 includes 2 valves V2 and V3 provided in the inert gas flow path 26a in addition to the valve V1 provided in the inert gas flow path 26 b. These valves V2 and V3 are valves that can be opened and closed by the control device 37, similarly to the valve V1. The valve V2 is disposed between the valve V1 and the low temperature heat medium tank 18, i.e., at the inlet side of the low temperature heat medium tank 18. The valve V3 is disposed between the valve V1 and the high temperature heat medium tank 17, i.e., on the inlet side of the high temperature heat medium tank 17.

The flow path switching unit 28 may be configured by a single valve (for example, a 3-port 4-position valve) or 2 valves as long as the communication state of the inert gas flow path system 6 (the inert gas flow paths 26a and 26b) can be switched by opening and closing control of the valves V1 to V3, which will be described later. The configuration of the flow path of the inert gas flow path system 6 is not limited to the configuration shown in fig. 2 as long as the necessary switching of the communication state can be achieved.

The CAES power generation apparatus 1 of the present embodiment includes an input device 38 communicably connected to the control device 37. The input device 38 receives an input of an instruction from an operator, and sends the input instruction to the control device 37. The input device 38 may also be connected to the control device 37 via a communication network to enable remote communication. The command sent from the input device 38 to the control device 37 includes an instruction to which of the 2 types of modes is set. The so-called 2 kinds of patterns are N₂A consumption amount reduction priority mode (1 st mode) and an electric power consumption amount reduction priority mode (2 nd mode).

In N₂In the consumption reduction priority mode, from N₂N of the gas cylinder 25 to the high temperature heating medium tank 17 and the low temperature heating medium tank 18₂reduction of the supply of gas, i.e. N₂the reduction of the gas consumption is more preferable than the reduction of the power consumption of the CAES power generation apparatus 1. In the power consumption reduction priority mode, the power consumption of the CAES generator 1 is reduced and N₂The reduction of the gas consumption is more preferred than the reduction of the gas consumption.

The controller 37 of the present embodiment controls the open/close states of the 3 valves V1 to V3 constituting the flow path switching unit 28, and switches the communication state of the inert gas flow paths 26a and 26b constituting the inert gas flow path system 6.

The CAES power generation apparatus 1 is performing either the charging operation or the power generation operation.

is set to N₂The consumption amount reduction priority mode and the power consumption amount reduction priority mode.

Whether or not the pressure P1 of the gas phase portion 17B of the high-temperature heat medium tank 17 detected by the pressure sensor 31A is equal to or greater than the pressure P2 of the gas phase portion 18B of the low-temperature heat medium tank 18 detected by the pressure sensor 31B.

In the charging operation of the CAES power generation apparatus 1, the valve V4 is set to be open because the heat medium flows from the low-temperature heat medium tank 18 to the high-temperature heat medium tank 17 through the heat medium flow path 19a by the pump 21A. In the charging operation of the CAES power generation apparatus 1, the pump 21B is stopped, the heat medium does not flow through the heat medium flow path 19B, and the valve V5 is set to be closed.

In the power generation operation of the CAES power generation apparatus 1, the valve V5 is set to be open because the heat medium flows from the high-temperature heat medium tank 17 to the low-temperature heat medium tank 18 through the heat medium flow path 19B by the pump 21B. In the charging operation of the CAES power generation apparatus 1, the pump 21A is stopped, the heat medium does not flow through the heat medium flow path 19a, and the valve V4 is set to be closed.

The control of the flow path switching unit 28 (valves V1 to V3) of the control device 37 will be described below with further reference to fig. 3 to 12. In the following description, the liquid level of the heating medium of the high temperature heating medium tank 17 is denoted by reference character h1, and the liquid level of the heating medium of the low temperature heating medium tank 18 is denoted by reference character h 2. Note that ρ represents the density of the heat medium, g represents the gravitational acceleration, and Δ PLc represents the pipe pressure loss of the heat medium flow path system 5.

(control during charging operation)

Referring to fig. 3, in step S1, it is judged that N is set₂The consumption amount reduction priority mode and the power consumption amount reduction priority mode. If set to N₂the flow proceeds to step S2 when the consumption amount reduction priority mode is set, and proceeds to step S5 when the power consumption amount reduction priority mode is set.

In step S2, it is determined whether or not the pressure P1 of the gas phase portion 17B of the high temperature heat medium tank 17 detected by the pressure sensor 31A is equal to or greater than the pressure P2 of the gas phase portion 18B of the low temperature heat medium tank 18 detected by the pressure sensor 31B.

If the pressure P1 is equal to or higher than the pressure P2 in step S2, the process proceeds to step S3.

Step S3 is the following case: is N₂In the charging operation in the consumption reduction priority mode, the pressure P1 of the gas phase portion 17b of the high-temperature heat medium tank 17 is equal to or higher than the pressure P2 of the gas phase portion 18b of the low-temperature heat medium tank 18. Referring to fig. 4, in step S3, the valve V1 is set to be closed, and the valves V2 and V3 are set to be opened. The high-temperature heat medium tank 17 and the low-temperature heat medium tank 18 are communicated with each other through the inert gas flow path 26a by opening and closing the valves V1 to V3. In addition, N₂The gas cylinder 25 is shut off from both the high temperature heat medium tank 17 and the low temperature heat medium tank 18 (state 1).

By setting the valves V1-V3 to the open/close setting shown in FIG. 4, N in the gas phase portion 17b of the high-temperature heat medium tank 17 is set₂The gas moves to the gas phase part 18b of the low temperature heat medium tank 18 through the inert gas flow path 26a until the pressure P1 of the high temperature heat medium tank 17 becomes equal to the pressure P2 of the low temperature heat medium tank 18 (P1 is equal to P2). Namely, by N through the inert gas passage 26a₂The gas moves, and the gas phase portion 17b of the high temperature heat medium tank 17 and the gas phase portion 18b of the low temperature heat medium tank 18 are equalized. Through the N₂The gas moves, the pressure P2 of the low temperature heat medium tank 18 rises, and the pressure P2 of the high temperature heat medium tank 17 falls. For this reason, the total head Δ P of the pump 21A is decreased by the amount of pressure increase required in the case where the gas phase part 17b of the high temperature heat medium tank 17 and the gas phase part 18b of the low temperature heat medium tank 18 are not communicated (P1-P2). That is, the power consumption of the pump 21A is reduced by the amount of pressure increase (P1-P2). The total head Δ P of the pump 21A is characterized by the following formula (1).

[ mathematical formula 1 ]

ΔP＝ρg(h1-h2)+ΔPLc (1)

Δ P: full lift of pump

ρ: density of heating medium

g: acceleration of gravity

h 1: the liquid level of the heating medium of the high temperature heating medium tank 17

h 2: the level of the heating medium of the high temperature heating medium tank 18

Δ PLc: pressure loss of piping

Until the pump 21A stops due to the end of the charging operation, the liquid level h1 of the heat medium in the high-temperature heat medium tank 17 rises and the liquid level h2 of the heat medium in the low-temperature heat medium tank 18 falls.

In the case where the pressure P1 is not the pressure P2 or more in step S2, that is, if the pressure P1 is less than the pressure P2, the process proceeds to step S4.

Step S4 is the following case: is N₂In the charging operation in the consumption reduction priority mode, the pressure P1 of the gas phase portion 17b of the high-temperature heat medium tank 17 is less than the pressure P2 of the gas phase portion 18b of the low-temperature heat medium tank 18. Referring to fig. 5, in step S4, the valve V1 is set to be closed (may be closed), and the valves V2 and V3 are set to be closed. By setting the opening and closing of V1-V3, the high temperature heat medium tank 17 and the low temperature heat medium tank 18 are blocked from each other, and N is set₂The gas cylinder 25 is blocked from both the high temperature heat medium tank 17 and the low temperature heat medium tank 18 (state 2).

When the valves V1 to V3 are opened and closed as shown in fig. 5, the high temperature heat medium tank 17 and the low temperature heat medium tank 18 are blocked from each other, and thus the pressure difference between the pressure P1 of the high temperature heat medium tank 17 and the pressure P2 of the low temperature heat medium tank 18 is maintained. Since the required pressure increase in the pump 21A is assisted by the amount of the pressure difference (P2-P1), the power consumption of the pump 21A decreases until the pressure P2 of the low-temperature heat medium tank 18 becomes lower than the pressure P1 of the high-temperature heat medium tank 17 (P2 < P1). In particular, when the following expression (2) is satisfied, the power consumption of the pump 21A becomes zero.

[ mathematical formula 2 ]

P2＝P1+ρg(h1-h2)+ΔPLc (2)

P2: pressure of gas phase of low-temperature heat medium tank

p1: pressure of gas phase of high-temperature heat medium tank

ρ: density of heating medium

g: acceleration of gravity

h 2: the level of the heating medium in the low temperature heating medium tank 18

Δ PLc: pressure loss of piping

Until the pump 21A stops due to the end of the charging operation, the liquid level h1 of the heat medium in the high temperature heat medium tank 17 rises, and the liquid level h2 of the heat medium in the low temperature heat medium tank 18 falls.

as described above, when the power consumption reduction priority mode is set in step S1, the process proceeds to step S5.

In step S5, it is determined whether or not the pressure P1 of the gas phase portion 17B of the high temperature heat medium tank 17 detected by the pressure sensor 31A is equal to or greater than the pressure P2 of the gas phase portion 18B of the low temperature heat medium tank 18 detected by the pressure sensor 31B.

If the pressure P1 is equal to or higher than the pressure P2 in step S5, the process proceeds to step S6.

Step S6 is a case where, during the charging operation in the power consumption reduction priority mode, the following is performed: the pressure P1 of the gas phase part 17b of the high temperature heat medium tank 17 is equal to or higher than the pressure P2 of the gas phase part 18b of the low temperature heat medium tank 18. Referring to fig. 6, in step S3, the valves V1 and V2 are set to be open, and the valve V3 is set to be closed. By setting the valves V1-V3 to be opened and closed, N₂The gas cylinder 25 communicates with the low-temperature heat medium tank 18 via the inert gas flow paths 26a, 26 b. In addition, the high temperature heat medium tank 17 is connected from the low temperature heat medium tank 18 and N₂The gas cylinder 25 is blocked (state 3).

The valves V1-V3 are set to the open/close setting shown in FIG. 6, so that the pressure in the valve N is increased₂The gas cylinder 25 supplies N to the low temperature heat medium tank 18 through the inert gas flow paths 26a, 26b₂A gas. As a result, the gas phase portion 17b of the high temperature heat medium tank 17 and the gas phase portion 18b of the low temperature heat medium tank 18 are equalized.

From N₂N from gas cylinder 25 to low-temperature heat medium tank 18₂The supply of the gas may be continued until the pressure P2 of the low temperature heat medium tank 18 becomes equal to the pressure P1 of the high temperature heat medium tank 17 (P2 — P1). In addition, from N₂N from gas cylinder 25 to low-temperature heat medium tank 18₂The supply of the gas may be continued even after the pressure P2 of the low temperature heat medium tank 18 is higher than the pressure P1 of the high temperature heat medium tank 17 (P2 > P1).

By passing from N until the pressures P1, P2 become equal₂The gas cylinder 25 supplies N to the low temperature heating medium tank 18₂The total head Δ P of the gas, pump 21A, is reduced by the amount of pressure increase required due to the low pressure of the low temperature heat medium tank 18 compared to the high temperature heat medium tank (P1-P2). That is, the power consumption of the pump 21A is reduced by the amount of pressure increase (P)1-P2). The total head Δ P of the pump 21A is characterized by the following formula (3).

[ mathematical formula 3 ]

ΔP＝ρg(h1-h2)+ΔPLc (3)

Δ P: full lift of pump

ρ: density of heating medium

g acceleration of gravity

Δ PLc: pressure loss of piping

By continuing to increase from N even after the pressure P2 of the low temperature heat medium tank 18 is higher than the pressure P1 of the high temperature heat medium tank 17₂n from gas cylinder 25 to low-temperature heat medium tank 18₂The power consumption of the pump 21A is further reduced by the supply of the gas. When the pressure of the gas phase portion 18b of the low-temperature heat medium tank 18 is P2 ═ P2 ' (P2 ' > P1), the pump 21A assists the pressure feed of the heat medium from the low-temperature heat medium tank 18 to the high-temperature heat medium tank 17 by the differential pressure (P2 ' -P1). In particular, when the following expression (4) is satisfied, the power consumption of the pump 21A becomes zero.

[ mathematical formula 4 ]

P2’＝P1+ρg(h1-h2)+ΔPLc (4)

P2': pressure of gas phase of low-temperature heat medium tank

P1: pressure of gas phase of high-temperature heat medium tank

ρ: density of heating medium

g: acceleration of gravity

h 1: the liquid level of the heating medium in the high level heating medium tank 17

Δ PLc: pressure loss of piping

In the case where the pressure P1 is not the pressure P2 or more in step S5, that is, if the pressure P1 is less than the pressure P2, the process proceeds to step S7.

Step S7 is an excellent power consumption reductionIn the charging operation in the previous mode, the following is the case: the pressure P1 of the gas phase part 17b of the high temperature heat medium tank 17 is less than the pressure P2 of the gas phase part 18b of the low temperature heat medium tank 18. Referring to fig. 7, in step S3, the valves V1 and V2 are set to be open, and the valve V3 is set to be closed. N is set by opening and closing these valves V1-V3₂The gas cylinder 25 communicates with the low-temperature heat medium tank 18 via the inert gas flow paths 26a, 26 b. In addition, the high temperature heat medium tank 17 is connected from the low temperature heat medium tank 18 and N₂The gas cylinder 25 is blocked (state 3). In other words, the opening and closing settings of the valves V1 to V3 in this case are the same as those in step S6 (fig. 6).

When the pressure of the gas phase portion 18b of the low-temperature heat medium tank 18 is P2 ═ P2 ' (P2 ' > P1), the pump 21A assists the pressure feed of the heat medium from the low-temperature heat medium tank 18 to the high-temperature heat medium tank 17 by the differential pressure (P2 ' -P1). In particular, when the above equation (4) is satisfied, the power consumption of the pump 21A becomes zero.

Until the pump 21A is stopped due to the end of the charging operation, the liquid level h1 of the heat medium in the high temperature heat medium tank 17 rises, and the liquid level h2 of the heat medium in the low temperature heat medium tank 18 falls.

(control during Power Generation operation)

Referring to fig. 8, it is determined in step S11 that N is set₂The consumption amount reduction priority mode and the power consumption amount reduction priority mode. If set to N₂The flow proceeds to step S12 when the consumption amount reduction priority mode is set, and proceeds to step S15 when the power consumption amount reduction priority mode is set.

It is judged at step S12 whether or not the pressure P1 of the gas phase part 17B of the high temperature heat medium tank 17 detected by the pressure sensor 31A is equal to or higher than the pressure P2 of the gas phase part 18B of the low temperature heat medium tank 18 detected by the pressure sensor 31B.

if the pressure P1 is equal to or higher than the pressure P2 in step S12, the process proceeds to step S13.

step S13 is the following case: is N₂In the power generation operation in the consumption reduction priority mode, the pressure P1 of the gas phase portion 17b of the high-temperature heat medium tank 17 is equal to or higher than the pressure P2 of the gas phase portion 18b of the low-temperature heat medium tank 18. Referring to fig. 9, in step S13, the valve V1 is set to be opened(may be set to be closed), and the valves V2 and V3 are set to be closed. The opening and closing settings of V1-V3 block the high temperature heat medium tank 17 and the low temperature heat medium tank 18 from each other, and N is set to be equal to₂the gas cylinder 25 is blocked from both the high temperature heat medium tank 17 and the low temperature heat medium tank 18 (state 2).

When the valves V1 to V5 are set to the open/close setting shown in fig. 9, the high temperature heat medium tank 17 and the low temperature heat medium tank 18 are blocked from each other, and therefore the pressure difference between the pressure P1 of the high temperature heat medium tank 17 and the pressure P2 of the low temperature heat medium tank 18 is maintained. Since the pressure increase required by the pump 21B is assisted by the pressure difference (P1-P2) by the corresponding amount, the power consumption of the pump 21B is reduced until the pressure P1 of the high-temperature heat medium tank 18 becomes lower than the pressure P2 of the low-temperature heat medium tank 17 (P1 < P2). In particular, when the following expression (5) is satisfied, the power consumption of the pump 21B becomes zero.

[ math figure 5 ]

P1＝P2+ρg(h1-h2)+ΔPLc (5)

P1: pressure of gas phase of high-temperature heat medium tank

P2: pressure of gas phase of low-temperature heat medium tank

ρ: density of heating medium

g: acceleration of gravity

Δ PLc: pressure loss of piping

Until the pump 21B stops due to the end of the power generating operation, the liquid level h1 of the heat medium in the high temperature heat medium tank 17 decreases, and the liquid level h2 of the heat medium in the low temperature heat medium tank 18 increases.

In the case where the pressure P1 is not the pressure P2 or more in step S12, that is, if the pressure P1 is less than the pressure P2, the process proceeds to step S14.

Step S14 is the following case: is N₂In the power generation operation in the consumption reduction priority mode, the pressure P1 of the gas phase portion 17b of the high-temperature heat medium tank 17 is less than the pressure P2 of the gas phase portion 18b of the low-temperature heat medium tank 18. Referring to fig. 10, in step S14, the valve V1 is set to be closed, and the valves V2 and V3 are set to be opened. The high-temperature heat medium tank is opened and closed by the valves V1-V317 and the low temperature heat medium tank 18 are communicated with each other via an inert gas flow path 26 a. In addition, N₂The gas cylinder 25 is shut off from both the high temperature heat medium tank 17 and the low temperature heat medium tank 18 (state 1).

By setting the valves V1-V3 to the open/close setting shown in FIG. 10, N in the gas phase portion 18b of the low-temperature heat medium tank 18 is set₂The gas moves to the gas phase part 17b of the high temperature heat medium tank 17 through the inert gas flow path 26a until the pressure P1 of the high temperature heat medium tank 17 becomes equal to the pressure P2 of the low temperature heat medium tank 18 (P1 is equal to P2). Namely, by N through the inert gas passage 26a₂The gas moves, and the gas phase portion 17b of the high temperature heat medium tank 17 and the gas phase portion 18b of the low temperature heat medium tank 18 are equalized. Through the N₂The gas moves, the pressure P2 of the low temperature heat medium tank 18 decreases, and the pressure P2 of the high temperature heat medium tank 17 increases. For this reason, the total head Δ P of the pump 21B is reduced by the amount of pressure increase required in the case where the gas phase part 17B of the high temperature heat medium tank 17 and the gas phase part 18B of the low temperature heat medium tank 18 are not communicated (P2-P1). That is, the power consumption of the pump 21B is reduced by the amount of pressure increase (P2-P1). The total head Δ P of the pump 21B is characterized by the following formula (6).

[ mathematical formula 6 ]

ΔP＝ρg(h2-h1)+ΔPLc (6)

Δ P: full lift of pump

ρ: density of heating medium

g: acceleration of gravity

Δ PLc: pressure loss of piping

As described above, when the power consumption reduction priority mode is set in step S11, the process proceeds to step S15.

In step S15, it is determined whether or not the pressure P1 of the gas phase portion 17B of the high temperature heat medium tank 17 detected by the pressure sensor 31A is equal to or greater than the pressure P2 of the gas phase portion 18B of the low temperature heat medium tank 18 detected by the pressure sensor 31B.

If the pressure P1 is equal to or higher than the pressure P2 in step S15, the process proceeds to step S16.

step S16 is a case where, during the power generation operation in the power consumption reduction priority mode, the following occurs: the pressure P1 of the gas phase part 17b of the high temperature heat medium tank 17 is equal to or higher than the pressure P2 of the gas phase part 18b of the low temperature heat medium tank 18. Referring to fig. 11, in step S16, the valves V1 and V3 are set to be open, and the valve V2 is set to be closed. By setting the valves V1-V3 to be opened and closed, N₂The gas cylinder 25 communicates with the high-temperature heat medium tank 17 via the inert gas flow paths 26a, 26 b. In addition, the low temperature heat medium tank 18 is connected from the high temperature heat medium tanks 17 and N₂The gas cylinder 25 is blocked (state 4).

When the pressure in the gas phase portion 17B of the high-temperature heat medium tank 17 is P1 ═ P1 ' (P1 ' > P2), the pump 21B assists the pressure feed of the heat medium from the high-temperature heat medium tank 17 to the low-temperature heat medium tank 18 by the differential pressure (P1 ' -P2). In particular, when the following expression (7) is satisfied, the power consumption of the pump 21A becomes zero.

[ mathematical formula 7 ]

P1’＝P2+ρg(h2-h1)+ΔPLc (7)

P1': pressure of gas phase of high-temperature heat medium tank

P2: pressure of gas phase of low-temperature heat medium tank

ρ: density of heating medium

g: acceleration of gravity

Δ PLc: pressure loss of piping

In the case where the pressure P1 is not the pressure P2 or more in step S15, that is, if the pressure P1 is less than the pressure P2, the process proceeds to step S17.

Step S17 is a case where, during the power generation operation in the power consumption reduction priority mode, the following occurs: the pressure P1 of the gas phase part 17b of the high temperature heat medium tank 17 is notThe pressure P2 of the gas phase part 18b of the foot low-temperature heating medium tank 18. Referring to fig. 12, in step S17, the valves V1 and V2 are set to be open, and the valve V3 is set to be closed. By setting the valves V1-V3 to be opened and closed, N₂The gas cylinder 25 communicates with the high-temperature heat medium tank 17 via the inert gas flow paths 26a, 26 b. In addition, the low temperature heat medium tank 18 is connected from the high temperature heat medium tanks 17 and N₂The gas cylinder 25 is blocked (state 4). In other words, the opening and closing settings of the valves V1 to V3 in this case are the same as those in step S16 (fig. 11).

The valves V1-V3 are set to the open/close setting shown in FIG. 12, so that the pressure in the valve N is increased₂The gas cylinder 25 supplies N to the high-temperature heat medium tank 17 through the inert gas flow paths 26a and 26b₂A gas. As a result, the gas phase portion 17b of the high temperature heat medium tank 17 and the gas phase portion 18b of the low temperature heat medium tank 18 are equalized.

From N₂N from gas cylinder 25 to high-temperature heat medium tank 17₂The supply of the gas may be continued until the pressure P1 of the high temperature heat medium tank 17 becomes equal to the pressure P2 of the low temperature heat medium tank 18 (P1 — P2). In addition, from N₂N from gas cylinder 25 to high-temperature heat medium tank 17₂The supply of the gas may be continued even after the pressure P1 of the high temperature heat medium tank 17 is higher than the pressure P2 of the high temperature heat medium tank 18 (P1 > P2).

By passing from N until the pressures P1, P2 become equal₂The gas cylinder 25 supplies N to the high temperature heating medium tank 17₂The full head Δ P of the gas, pump 21A is reduced by the amount of pressure increase required due to the low pressure of the high temperature heat medium tank 17 than the low temperature heat medium tank 18 (P2-P1). That is, the power consumption of the pump 21B is reduced by the amount of pressure increase (P2-P1). The total head Δ P of the pump 21B is characterized by the following formula (8).

[ mathematical formula 8 ]

ΔP＝ρg(h2-h1)+ΔPLc (8)

Δ P: full lift of pump

ρ: density of heating medium

g: acceleration of gravity

Δ PLc: pressure loss of piping

By continuing to increase from N even after the pressure P1 of the high temperature heat medium tank 17 is higher than the pressure P2 of the low temperature heat medium tank 18₂N from gas cylinder 25 to high-temperature heat medium tank 17₂The power consumption of the pump 21B is further reduced by the supply of the gas. When the pressure in the gas phase portion 17B of the high-temperature heat medium tank 17 is P1 ═ P1 ' (P1 ' > P2), the pump 21B assists the pressure feed of the heat medium from the low-temperature heat medium tank 18 to the high-temperature heat medium tank 17 by the differential pressure (P1 ' -P2). In particular, when the above equation (7) is satisfied, the power consumption of the pump 21B becomes zero.

in embodiments 3 and 4 of the present invention described below, the device configuration of the CAES power generation apparatus 1 is the same as that of embodiment 2 (fig. 2). Therefore, the control of the flow path switching unit 28 by the control device 37 will be described with respect to these embodiments, and fig. 2 will be referred to for the device configuration.

(embodiment 3)

The controller 37 switches the communication state of the inert gas flow paths 26a and 26b constituting the inert gas flow path system 6 by controlling the open/close states of the 3 valves V1 to V3 constituting the flow path switching unit 28 as follows.

Should be such that N is₂The consumption reduction and the power consumption reduction are prioritized.

In the present embodiment, unlike embodiment 2, N is not input to the control device 37₂The consumption amount reduction priority mode and the power consumption amount reduction priority mode. In the present embodiment, the controller 37 determines that it is to be necessary to determine the pressure based on, for example, the pressure P1 of the gas phase portion 17b of the high-temperature heat medium tank 17, the pressure P2 of the gas phase portion 18b of the low-temperature heat medium tank 18, the power consumption of the CAES apparatus 1, and the likeMake N₂the consumption reduction and the power consumption reduction are prioritized.

(control during charging operation)

Referring to fig. 13, it is judged at step S21 whether the pressure P1 of the gas phase part 17B of the high temperature heat medium tank 17 detected by the pressure sensor 31A is equal to or greater than the pressure P2 of the gas phase part 18B of the low temperature heat medium tank 18 detected by the pressure sensor 31B. If the pressure P1 is equal to or higher than the pressure P2, the process proceeds to step S22, and if the pressure P1 is lower than the pressure P2, the process proceeds to step S25.

In step S22, it is determined whether or not to reduce the power consumption and N₂Consumption reduction is more preferred than consumption reduction. When the priority is to be lowered for the power consumption, the process proceeds to step S23, where N is set₂If the consumption reduction priority is given, the process proceeds to step S24.

In step S23, in the charging operation in which priority is given to reduction of the amount of power consumption, the following is performed: the pressure P1 of the gas phase part 17b of the high temperature heat medium tank 17 is equal to or higher than the pressure P2 of the gas phase part 18b of the low temperature heat medium tank 18. Referring to fig. 6, in step S23, the valves V1 and V2 are set to be open, and the valve V3 is set to be closed. N is set by opening and closing the valves V1-V3₂The gas cylinder 25 communicates with the low-temperature heat medium tank 18 via the inert gas flow paths 26a, 26 b. In addition, the high temperature heat medium tank 17 is connected from the low temperature heat medium tank 18 and N₂The gas cylinder 25 is blocked (state 3).

As described in step S6 of embodiment 2, the valves V1 to V3 can be opened and closed from N by setting the valves to the open and close settings shown in fig. 6₂N from gas cylinder 25 to low-temperature heat medium tank 18₂The supply of the gas reduces the power consumption of the pump 21A.

In step S24, N is₂In the charging operation with priority for reducing the consumption amount, the following cases are assumed: the pressure P1 of the gas phase part 17b of the high temperature heat medium tank 17 is equal to or higher than the pressure P2 of the gas phase part 18b of the low temperature heat medium tank 18. Referring to fig. 4, in step S24, the valve V1 is set to be closed, and the valves V2 and V3 are set to be opened. The high-temperature heat medium tank 17 and the low-temperature heat medium tank 18 are communicated with each other through the inert gas flow path 26a by opening and closing the valves V1 to V3. In addition, N₂The gas cylinder 25 is charged from the high-temperature heating medium tank 17 andBoth of the low temperature heat medium tanks 18 are shut off (state 1).

As described in connection with step S3 of embodiment 2, the valves V1 to V3 are set to the open/close settings shown in fig. 4, whereby N passing through the inert gas flow passage 26a passes through₂The movement of the gas equalizes the pressure of the gas phase part 17b of the high temperature heat medium tank 17 and the gas phase part 18b of the low temperature heat medium tank 18. In addition, the power consumption of the pump 21A reduces the amount of pressure increase required when the gas phase portion 17b of the high temperature heat medium tank 17 and the gas phase portion 18b of the low temperature heat medium tank 18 are not in communication (P1-P2).

in step S25, it is determined whether to reduce the power consumption and N₂consumption reduction is more preferred than consumption reduction. When the priority is to be lowered for the power consumption, the process proceeds to step S26, where N is set₂If the consumption reduction priority is given, the process proceeds to step S27.

In step S26, in the charging operation in which priority is given to reduction of the amount of power consumption, the following is the case: the pressure P1 of the gas phase part 17b of the high temperature heat medium tank 17 is less than the pressure P2 of the gas phase part 18b of the low temperature heat medium tank 18. Referring to fig. 7, in step S26, the valves V1 and V2 are set to be open, and the valve V3 is set to be closed. By setting the valves V1-V3 to be opened and closed, N₂The gas cylinder 25 communicates with the low-temperature heat medium tank 18 via the inert gas flow paths 26a, 26 b. In addition, the high temperature heat medium tank 17 is connected from the low temperature heat medium tank 18 and N₂The gas cylinder 25 is blocked (state 3).

As described in step S7 of embodiment 2, the valves V1 to V3 can be opened and closed from N by setting the valves to the open and close settings shown in fig. 7₂N from gas cylinder 25 to low-temperature heat medium tank 18₂The supply of the gas reduces the power consumption of the pump 21A.

In step S27, N is₂In the charging operation with priority for reducing the consumption amount, the following cases are assumed: the pressure P1 of the gas phase part 17b of the high temperature heat medium tank 17 is less than the pressure P2 of the gas phase part 18b of the low temperature heat medium tank 18. Referring to fig. 5, in step S27, the valve V1 is set to be closed (set to be closed), and the valves V2 and V3 are set to be closed. By setting the opening and closing of V1-V3, the high temperature heat medium tank 17 and the low temperature heat medium tank 18 are blocked from each other and N is set₂The gas cylinder 25 is heated from the high temperature heating medium tank 17 and the low temperature heatMedia canister 18 is blocked on both sides (state 2).

As described in connection with step S4 of embodiment 2, the pressure increase required in the pump 21A is assisted by the pressure difference (P2-P1) between the high temperature heat medium tank 17 and the low temperature heat medium tank 18 by setting the valves V1 to V3 to the open/close settings shown in fig. 5, thereby reducing the power consumption of the pump 21A.

(control during Power Generation operation)

Referring to fig. 14, it is judged at step S31 whether the pressure P1 of the gas phase part 17B of the high temperature heat medium tank 17 detected by the pressure sensor 31A is equal to or greater than the pressure P2 of the gas phase part 18B of the low temperature heat medium tank 18 detected by the pressure sensor 31B. If the pressure P1 is equal to or higher than the pressure P2, the process proceeds to step S32, and if the pressure P1 is lower than the pressure P2, the process proceeds to step S35.

in step S32, it is determined whether to reduce the power consumption and N₂Consumption reduction is more preferred than consumption reduction. When prioritizing the power consumption reduction, the process proceeds to step S33, where N is set₂When the consumption amount reduction priority is given, the process proceeds to step S34.

In step S33, during the power generation operation in which priority is given to power consumption reduction, the following occurs: the pressure P1 of the gas phase part 17b of the high temperature heat medium tank 17 is equal to or higher than the pressure P2 of the gas phase part 18b of the low temperature heat medium tank 18. Referring to fig. 11, in step S33, the valves V1 and V3 are set to be open, and the valve V2 is set to be closed. By setting the valves V1-V3 to be opened and closed, N₂The gas cylinder 25 communicates with the high-temperature heat medium tank 17 via the inert gas flow paths 26a, 26 b. In addition, the low temperature heat medium tank 18 is connected from the high temperature heat medium tanks 17 and N₂The gas cylinder 25 is blocked (state 4).

As described in step S16 of embodiment 2, the valves V1 to V3 can be opened and closed from N by setting the valves to the open and close settings shown in fig. 11₂N from gas cylinder 25 to high-temperature heat medium tank 17₂The supply of the gas reduces the power consumption of the pump 21B.

Step S34 is the following case: is such that N is₂In the power generation operation in which the consumption amount reduction priority is given, the pressure P1 of the gas phase portion 17b of the high-temperature heat medium tank 17 is equal to or higher than the pressure P2 of the gas phase portion 18b of the low-temperature heat medium tank 18. If reference is made to FIG. 9, then at stepAt S34, the valve V1 is set to be closed (may be closed), and the valves V2 and V3 are set to be closed. The opening and closing settings of V1-V3 block the high temperature heat medium tank 17 and the low temperature heat medium tank 18 from each other, and N is set to be equal to₂the gas cylinder 25 is blocked from both the high temperature heat medium tank 17 and the low temperature heat medium tank 18 (state 2).

as described in connection with step S13 of embodiment 2, the pressure increase required for the pump 21B is assisted by the pressure difference (P1-P2) between the high temperature heat medium tank 17 and the low temperature heat medium tank 18 by setting the valves V1 to V3 to the open/close settings shown in fig. 9, thereby reducing the power consumption of the pump 21B.

In step S35, it is determined whether to reduce the power consumption and N₂Consumption reduction is more preferred than consumption reduction. When the priority is to be lowered for the power consumption, the process proceeds to step S36, where N is set₂If the consumption reduction priority is given, the process proceeds to step S37.

In step S36, in the charging operation in which priority is given to reduction of the amount of power consumption, the following is the case: the pressure P1 of the gas phase part 17b of the high temperature heat medium tank 17 is less than the pressure P2 of the gas phase part 18b of the low temperature heat medium tank 18. Referring to fig. 12, in step S36, the valves V1 and V3 are set to be open, and the valve V2 is set to be closed. By setting the valves V1-V3 to be opened and closed, N₂The gas cylinder 25 communicates with the high-temperature heat medium tank 17 via the inert gas flow paths 26a, 26 b. In addition, the low temperature heat medium tank 18 is connected from the high temperature heat medium tanks 17 and N₂The gas cylinder 25 is blocked (state 4).

As described in connection with step S17 of embodiment 2, by setting the valves V1 to V3 to the open/close setting shown in fig. 12, N from the N2 gas cylinder 25 to the high-temperature heat medium tank 17 can pass through₂The supply of the gas reduces the power consumption of the pump 21B.

In step S37, N is₂In the charging operation with priority for reducing the consumption amount, the following cases are assumed: the pressure P1 of the gas phase part 17b of the high temperature heat medium tank 17 is less than the pressure P2 of the gas phase part 18b of the low temperature heat medium tank 18. Referring to fig. 10, in step S37, the valve V1 is set to be closed, and the valves V2 and V3 are set to be opened. By opening and closing the valves V1 to V3, the high temperature heat medium tank 17 and the low temperature heat medium tank 18 communicate with each other through the inert gas flow path 26 a. In additionOuter, N₂The gas cylinder 25 is blocked from both the high temperature heat medium tank 17 and the low temperature heat medium tank 18 (state 1).

As described in connection with step S14 of embodiment 2, by setting the valves V1 to V3 to the open/close setting shown in fig. 10, N passing through the inert gas flow passage 26a can pass through₂The movement of the gas equalizes the pressure of the gas phase part 17b of the high temperature heat medium tank 17 and the gas phase part 18b of the low temperature heat medium tank 18. In addition, the power consumption of the pump 21B reduces the amount of pressure increase required in the case where the gas phase part 17B of the high temperature heat medium tank 17 and the gas phase part 18B of the low temperature heat medium tank 18 are not communicated (P2-P1).

(embodiment 4)

The CAES power generation apparatus 1 performs either the charging operation or the power generation operation.

In the present embodiment, N is always set to be N without performing the control of the power consumption reduction priority mode corresponding to embodiment 2₂The consumption reduction takes precedence.

Referring to fig. 15, in the charging operation, it is determined at step S41 whether the pressure P1 of the high temperature heat medium tank 17 detected by the pressure sensor 31A is equal to or greater than the pressure P2 of the low temperature heat medium tank 18 detected by the pressure sensor 31B. If the pressure P1 is equal to or higher than the pressure P2, the process proceeds to step S42, and if the pressure P1 is lower than the pressure P2, the process proceeds to step S43. In step S42, the open/close states of the valves V1 to V3 are set as shown in fig. 4. In step S43, the open/close states of the valves V1 to V3 are set as shown in fig. 5.

Referring to fig. 16, in the power generating operation, it is determined at step S51 whether the pressure P1 of the high temperature heat medium tank 17 detected by the pressure sensor 31A is equal to or greater than the pressure P2 of the low temperature heat medium tank 18 detected by the pressure sensor 31B. If the pressure P1 is equal to or higher than the pressure P2, the process proceeds to step S52, and if the pressure P1 is lower than the pressure P2, the process proceeds to step S53. In step S52, the open/close states of the valves V1 to V3 are set as shown in fig. 9. In step S43, the open/close states of the valves V1 to V3 are set as shown in fig. 10.

Description of reference numerals

1 compressed air storage (CAES) power generation device

2 generating set

3 electric power system

4 air flow path system

5 heat medium flow path system

6 inert gas flow path system

8 compressor

8a suction inlet

8b spout

9 st 1 heat exchanger

10 pressure accumulating tank (pressure accumulating part)

11 nd 2 nd heat exchanger

12 expansion machine

12a air supply port

12b exhaust port

13a to 13d air flow path

14 motor

15 electric generator

17 high temperature heating medium tank (high temperature heat storage part)

17a liquid phase part

17b gas phase part

18 low temperature heating medium tank (Low temperature heat storage part)

18a liquid phase part

18b gas phase part

19a, 19b heat medium flow path

21A, 21B pump

22A, 22B check valve

25 N₂Gas cylinder (inert gas source)

26a, 26b inert gas flow path

27 pressure reducing valve

28 flow channel switching part

31A, 31B pressure sensor

32A, 32B safety valve

34 compressor assembly

35 Generator assembly

37 control device

38 input device

Claims

1. A compressed air storage power generation device is characterized by comprising:

A motor driven by a variable input power;

A compressor mechanically connected to the motor for compressing air;

A pressure accumulation unit that is fluidly connected to the compressor and that accumulates compressed air generated by the compressor;

An expander fluidly connected to the accumulator and driven by the compressed air supplied from the accumulator;

A generator mechanically connected to the expander;

A 1 st heat exchanger for exchanging heat between the compressed air generated by the compressor and a heat medium to raise the temperature of the heat medium;

A high-temperature heat storage unit which is fluidly connected to the 1 st heat exchange unit and stores the heat medium after the heat exchange in the 1 st heat exchange unit;

A 2 nd heat exchange unit fluidly connected to the high-temperature heat storage unit, for performing heat exchange between the heat medium supplied from the high-temperature heat storage unit and the compressed air supplied from the heat storage unit to the expander to raise a temperature of the compressed air;

A low-temperature heat storage unit which is fluidly connected to the 2 nd heat exchange unit and stores the heat medium subjected to heat exchange in the 2 nd heat exchange unit;

An inert gas source that provides an inert gas;

An inert gas flow path system that fluidly connects the gas phase portion of the high-temperature heat storage portion, the gas phase portion of the low-temperature heat storage portion, and the inert gas source to each other; and

A flow path switching unit capable of switching at least a state in which the inert gas flow path system is in communication with both the high-temperature heat storage unit and the low-temperature heat storage unit and a state in which the inert gas source is blocked from both the high-temperature heat storage unit and the low-temperature heat storage unit.

2. The compressed air storage power plant of claim 1,

The compressed air storage power generation device further includes: a control unit that controls the flow path switching unit,

The state of the inert gas flow path system switchable by the flow path switching unit includes:

A 1 st state in which the high-temperature heat storage portion and the low-temperature heat storage portion are in communication with each other, and the inert gas source is blocked from both the high-temperature heat storage portion and the low-temperature heat storage portion;

a 2 nd state in which the high-temperature heat storage portion and the low-temperature heat storage portion are blocked from each other, and the inert gas source is blocked from both the high-temperature heat storage portion and the low-temperature heat storage portion;

A 3 rd state in which the inert gas source is communicated with the low-temperature heat storage portion, and the high-temperature heat storage portion is blocked from the low-temperature heat storage portion and the inert gas source; and

A 4 th state in which the inert gas source communicates with the high-temperature heat storage portion, while the low-temperature heat storage portion is blocked from the high-temperature heat storage portion and the inert gas source,

The control unit switches the inert gas flow path system to any one of the 1 st to 4 th states through the flow path switching unit based on at least one of a charging operation and a power generation operation and whether or not a 1 st pressure is a pressure of the gas phase of the high-temperature heat storage unit and a 2 nd pressure is a pressure of the gas phase of the low-temperature heat storage unit.

3. The compressed air storage power plant of claim 2,

The compressed air storage power generation device is capable of being set to a 1 st mode in which reduction of inert gas consumption is prioritized over reduction of power consumption and a 2 nd mode in which reduction of power consumption is prioritized over reduction of inert gas consumption,

In the charging operation in the 1 st mode, when the 1 st pressure is equal to or higher than the 2 nd pressure, the control unit switches the inert gas flow path to the 1 st state by the flow path switching unit,

In the charging operation in the 1 st mode, if the 1 st pressure is not equal to or higher than the 2 nd pressure, the control unit switches the inert gas flow path to the 2 nd state by the flow path switching unit,

In the charging operation in the 2 nd mode, the control unit switches the inert gas flow path to the 3 rd state by the flow path switching unit.

4. The compressed air storage power plant of claim 3,

In the power generation operation in the 1 st mode, when the 1 st pressure is equal to or higher than the 2 nd pressure, the control unit switches the inert gas flow path to the 2 nd state by the flow path switching unit,

In the power generating operation in the 1 st mode, if the 1 st pressure is not equal to or higher than the 2 nd pressure, the control unit switches the inert gas flow path to the 1 st state by the flow path switching unit,

In the power generating operation in the 2 nd mode, the control unit switches the inert gas flow path to the 4 th state by the flow path switching unit.

5. The compressed air storage power plant of claim 2,

In the charging operation, when the 1 st pressure is equal to or higher than the 2 nd pressure, the control unit switches the inert gas flow path to the 1 st state by the flow path switching unit,

when the 1 st pressure is not equal to or higher than the 2 nd pressure, the control unit switches the inert gas flow path to the 2 nd state by the flow path switching unit.

6. The compressed air storage power plant of claim 2,

In the power generating operation, when the 1 st pressure is equal to or higher than the 2 nd pressure, the control unit switches the inert gas flow path to the 2 nd state by the flow path switching unit,

In the power generating operation, when the 1 st pressure is not equal to or higher than the 2 nd pressure, the control unit switches the inert gas flow path to the 1 st state by the flow path switching unit.

7. A method for storing compressed air to generate power is characterized in that,

Preparing a compressed air storage power generation device, the compressed air storage power generation device comprising:

A motor driven by a variable input power;

A compressor mechanically connected to the motor for compressing air;

A heat storage unit that is fluidly connected to the compressor and stores compressed air generated by the compressor;

An expander fluidly connected to the heat storage unit and driven by the compressed air supplied from the heat storage unit;

a generator mechanically connected to the expander;

A high-temperature heat storage unit which is fluidly connected to the 1 st heat exchange unit and stores the heat medium subjected to heat exchange in the 1 st heat exchange unit;

a 2 nd heat exchanger fluidly connected to the high-temperature heat storage tank, for performing heat exchange between a heat medium supplied from the high-temperature heat storage unit and the compressed air supplied from the heat storage unit to the expander to raise a temperature of the compressed air;

An inert gas source that provides an inert gas;

A flow path switching unit capable of switching between a communication state and a blocking state of the inert gas flow path system,

The inert gas flow path system is switched to any of the 1 st to 4 th states based on at least which of a charging operation and a power generation operation the compressed air storage power generation device is in, and whether or not a 1 st pressure is a 2 nd pressure or more, the 1 st pressure being a pressure of the gas phase of the high-temperature heat storage portion, the 2 nd pressure being a pressure of the gas phase of the low-temperature heat storage portion.